The present invention relates to a peak limiter intended to limit the peak of a signal that has a given frequency, in an assembly comprising other signals whose amplitude is lower than that of said signal and whose frequencies are different.
The invention furthermore relates to a network for distributing television signals by cable, comprising an arrangement for processing telephone signals, for example, of the GSM type, which arrangement includes, inter alia, a transceiver antenna and a circuit separating a receive channel from a transmit channel, the arrangement including a peak limiter in the receive channel.
U.S. Pat. No. 4,641,365 describes a diplexer system having a transmit and a receive branch, which system comprises a peak limiter placed in its receive branch; this peak limiter is formed by only two diodes arranged in inverse parallel relationship without frequency selectivity.
It is an object of the invention to provide a frequency-selective peak limiter which is simple and has high performance.
For this purpose, the peak limiter comprises, inserted into a line transporting all the signals, a circulator whose first branch is connected to the line on its upstream side, whose second branch is connected to the line on its downstream side and whose third branch is connected to a reference terminal via the combination of a band-pass filter centered on said given frequency, a threshold element, and an adapted load connected in series.
Particular embodiments of the peak limiter appear in the dependent claims 2 and 3.
A network for distributing television signals by cable advantageously includes a peak limiter according to the invention inserted into the receive channel, of which the first branch of the circulator is connected to the antenna and of which the second branch is connected to a downstream part of the channel.
A particular embodiment of the network will appear in the dependent claim 5.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.